LOS ANGELES—An effort to speed up construction of the subway to the sea in Los Angeles has received a boost from the Obama administration.

Senator Barbara Boxer said Friday that the Federal Transit Administration has agreed to accelerate review of the 9-mile segment. That will help get the project shovel-ready for when officials secure funding for it.

Boxer said she also received a letter from Transportation Secretary Ray LaHood supporting a local plan to accelerate construction of a dozen transit projects by borrowing from the federal government.

In 2008, Los Angeles County voters agreed to increase the sales tax to raise about $40 billion for transportation improvements over a 30-year period. Under the "30/10" plan, local officials propose completing those projects in 10 years by borrowing from Washington.